Regeneration or purification of lubricating oils



Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE HORACE JOHN YOUNG, OFVIESTMINSTEB, ENGLAND, ASSIGNOR OF ONE-HALF TO SWAN, HUNTER & WIGHAMRICHARDSON LIMITED, OF NEWCASTLE-UPON-TYNE, ENGLAND,

AN ENGLISH COMPANY REGENERATION OR PURIFICATION OF LUBRICATING OILSApplication filed March 22, 1928, Serial No. 263,946, and in GreatBritain April 12, 1927.

This invention relates to the regeneration or purification oflubricating oils as used for example in connection with the lubricationof engines or Of other machinery in which the oil is liable to becontaminated or become altered in such a manner as to render itcorrosive or otherwise detrimental to the materials with which it comesinto contact.

Oils drawn from the lubrication systems of motor engineseither marine,land or aviationare found sometimes to be corrosive to steel or whitebearing metal or both. This corrosive property appears to be caused in anumber of cases by active sulphates such as are found to be present insuch oils after but not before use. Such sulphates may be chemicallydetected or determined in aqueous solutions obtained by digestion of theoil in caustic soda or potash, although however there appeared to existno test for their detection prior to my having established, as a resultof investigations, the fact that lubricating oils, which, tested by theusual recognized chemical methods for acidity, appeared to present noabnormalities or anything to suggest that they might be corrosive,nevertheless possessed in fact corrosive properties the efiects of whichwere found in practice to be of a very serious character.

Contamination of lubricating oils whereby they acquire corrosiveproperties may be due to solid, liquid or gaseous matters from thecombustion chambers or zones of internal combustion engines mixing withthe lubricating oil, or may be due to salt water or chemical eifiuentsor other injurious matters which may be of an acid or alkaline naturegaining access to the said oils. In other cases the corrosive propertiesmay be due to deterioration of the lubricating oil itself or to theoriginal nature of the lubricating oil as supplied. It is very desirableand important that any corrosive condition of the lubricating oil shouldbe corrected or avoided and the objects of the present invention are toaccomplish these results.

For this purpose according to the present invention the lubricating oilis treated by bringing it into intimate contact with a nonferrous metalor metals or an alloy of non ferrous metals reactive with the corrosiveingredients present in the oil but without producing reaction productshaving the same deleterious effects as those of the aforesaid corrosiveingredients. Examples of substances suitable for use for suchpurification of lubricating oils are metallic zinc, aluminium,magnesium, or alloys of two or all of the aforesaid metals, or alloys ofcalcium or sodium or of calcium and sodium with one or more of theaforesaid metals.

The treatment of the lubricating oil with the purifying reagent can beeffected in the oil supply or circulating system or in some outside tankor plant. The purifying reagent is used in the form of solid, hollow orperforated plates, bars, or wires, or in the form of granules or smallparticles, or in any other convenient form to constitute a regeneratoror purifier that will provide for a large surface of contact with theimpure oil to be treated; for example the regenerator or purifier, whichmay be in the form of a chamber or tank or of one or more straight orsuitably bent pipes, can be constructed of or lined with or otherwiseprovided with zinc or other nonferrous metal or alloy hereinbeforestated with which the impure lubricating oil to be treated is broughtinto contact.

As an example of the treatment of a lubricating oil according to thepresent invention there may be instanced that of a mineral oil drawnfrom a marine engine. Before use in the engine this oil was a recognizedmineral lubricant having a flash point of 297 F. a

specific gravity of 0.8893, and a Redwood viscosity of 104;? seconds at70 F., whilst it contained no sulphates according to my special testtherefor and was not corrosive either to a steel or white bearingmetal.After having been used in the engine the lubricating oil in questiondrawn therefrom. although showing no content of mineral acidwhensubjected to the usual recognized tests for such heretoforeemployed, nevertheless was found to i be highly corrosive to both steeland white bearing metal. and further was shown to contain an actualamount of 0.149 percent sulphates when it was subjected to the specialnial ea {p e -mu h ma te ed t9? the determination of sulphates devisedby me. This corrosive oil was then warmed for about seven hours inintimate contact with a large area of Zinc. after which treatment itscorrosive properties were found to have been entirely removed. I havefound that as little as 00188 per cent SO added as concentratedsulphuric acid to an uncorrosive oil caused that oil to; becomecorrosive both to steel and white bearing metal, even though it couldnot be detected by the usual recognized mineral acid test heretoforeinuse. Thisoil however was again rendered inocuous both to steel and whitebearing metal by bringing it into contact with zinc. It has been foundthat although the purifying action of the non-ferrous metal or alloytakes efiect when the oil is cold itis expedited when the oil is warm. cV

In one method of carrying the invention into effect, the lubricating oilunder treatment is continuously circulated through a purifying chamberor chambers arranged and constructed so that it or they can be easilyinspected. cleaned and overhauled without the stoppage of thecirculation of the lubricating oil in the oil circulating system of theengine or other machinery. One construction of purifying chamber or tankadapted for carrying out the process according to the'present inventionis illustrated in the accompanying drawings in which Figure 1 is avertical section.

Figure 2 is a transverse section of the line a, a of Figure 1, and vFigure 3 is a fragmentary plan view partly in section. v V

The purifying chamber or tank constituting in the particular exampleshown the regenerator orpurifier comprises a cast-iron body portion 1 inthe interior of which are arranged steel supportingplates 2 retained inposition by steel distance pieces 3 the re- 1. A process for freeingused lubricating oil from corrosive impurities which consists inbringing the oil to be treated into intimate contact with a non-ferrousmetallic substance reactive with the corrosive ingredients of the oilwithout producing reaction products having the same deleterious effectsas those of the aforesaid corrosive ingredients. 7

2. A process as in claim 1 in which the reactive substance employedcomprises a non- Y ferrous metal.

3. A process as in claim 1 in which the reactive substance comprisesmetallic zinc.

4. A process as in claim 1 in which the re active substance has a largesurface of contact with the oil to be treated.

55. A process as in claim 1 in which the reactive substance comprisesmetalllc zinc having a large surface of contact w1th the oil.

6. A process as in claim 1 in which the oil is warmed for several hourswhile in intimate contact with the reactive substance.

7. A process as in claim 1 in'which the oil is warmed for several hourswhile in intimate contact with metallic zinc. v

8. A process as in claim 1 in which the oil is warmed for several hourswhile in intimate contact with a large area of metallic zinc.

HORACE JOHN YOUNG.

duced ends of which pass through holes 4:

in the plates and are fitted with ferrules 5. Through holes 6 in thesteel plates there are insertedzinc rods 7 which occupy substantiallythe whole interior space of the tank, and over which rods the oil to betreated flows in its passage therethrough, entering by the inlet 8 andleaving by the outlet 9. The tank is provided with an easily removablecast-iron cover .10. so that the parts of the whole apparatus are easilyaccessible for cleaning or' renewalpurposes when desired. For heatingthe purifying chamber or tank, there may be provided a .heating jacketsurounding the tank, as diagrammatically shown in dotted lines in Figure1, such tank having an inlet A and an outlet B for the heating medium. Asuitable location for the tank is to insert it in the circuit betweenthe settling tank for lu bricating oil discharged from the system andthe sumpsor reservoir from which the lubriseating oil enters the systemfor its circulation

